The function analyses CW-OSL curve data produced by a SUERC portable OSL reader and produces a combined plot of OSL/IRSL signal intensities, OSL/IRSL depletion ratios and the IRSL/OSL ratio.
analyse_portableOSL(
object,
signal.integral = NULL,
invert = FALSE,
normalise = FALSE,
mode = "profile",
coord = NULL,
plot = TRUE,
...
)Returns an S4 RLum.Results object with the following elements:
$data
.. $summary: data.frame with the results
.. $data: list with the RLum.Analysis objects
.. $args: list the input arguments
RLum.Analysis (required): object produced by read_PSL2R. The input can be a list of such objects, in which case each input is treated as a separate sample and the results are merged.
numeric (required):
A vector specifying the range of channels used to calculate the OSL/IRSL
signal. It can be provided as a vector of length 2 such as c(1, 5), or
as a sequence such as 1:5, in which case the lowest and highest values
define the range.
logical (with default): TRUE flip the plot the data in reverse order.
logical (with default): whether the OSL/IRSL signals should be normalised to the mean of all corresponding data curves.
character (with default):
analysis mode, one of "profile" (the default) or "surface" for surface
interpolation.
list matrix (optional): a list or a 2-column matrix
with the x and y coordinates for the sampling positions in meters (m),
of the same length as the number of samples measured. For example, the
coordinates for one sample could be coord = list(samp1 = c(0.1, 0.2).
If the x coordinates were not measured, x should be set to 0.
Note that, in such case, a surface plot cannot be produced.
logical (with default): enable/disable the plot output.
other parameters to be passed to modify the plot output.
Supported are run to provide the run name (if the input is a list, this
is set automatically). Further plot parameters accepted are main,
col, xlim (a named list for profile mode), ylim, ylab, xlab.
Additional parameters for mode = "profile" are type, pch, grid
(TRUE/FALSE), bg_img (a raster object for the background image,
usually a profile photo), bg_img_positions (a vector with the four corner
positions, see graphics::rasterImage), zlab (here x-axis labelling).
Additional parameters for mode = "surface" are surface_value
(character with names of the surfaces to plot), col_ramp, legend
(TRUE/FALSE), contour (TRUE/FALSE), contour_nlevels, contour_col, ' zlim.
0.1.3
Christoph Burow, University of Cologne (Germany)
Sebastian Kreutzer, Institute of Geography, Heidelberg University (Germany)
Marco Colombo, Institute of Geography, Heidelberg University (Germany)
, RLum Developer Team
Burow, C., Kreutzer, S., Colombo, M., 2025. analyse_portableOSL(): Analyse portable CW-OSL measurements. Function version 0.1.3. In: Kreutzer, S., Burow, C., Dietze, M., Fuchs, M.C., Schmidt, C., Fischer, M., Friedrich, J., Mercier, N., Philippe, A., Riedesel, S., Autzen, M., Mittelstrass, D., Gray, H.J., Galharret, J., Colombo, M., Steinbuch, L., Boer, A.d., 2025. Luminescence: Comprehensive Luminescence Dating Data Analysis. R package version 1.1.1. https://r-lum.github.io/Luminescence/
This function only works with RLum.Analysis objects produced by read_PSL2R.
It further assumes (or rather requires) an equal amount of OSL and IRSL curves that
are pairwise combined for calculating the IRSL/OSL ratio.
For calculating the depletion ratios, the cumulative signal of the last n
channels (same number of channels as specified by signal.integral) is
divided by cumulative signal of the first n channels (signal.integral).
Note: The function assumes the following sequence pattern:
DARK COUNT, IRSL, DARK COUNT, BSL, DARK COUNT. Therefore, the
total number of curves in the input object must be a multiple of 5, and
there must be 3 DARK_COUNT records for each IRSL/BSL pair. If you have used
a different sequence, the function will produce an error.
Signal processing
The function processes the signals as follows: BSL and IRSL signals are extracted using the
chosen signal integral, dark counts are taken in full.
Working with coordinates Usually samples are taken from a profile with a certain stratigraphy. In the past the function calculated an index. With this newer version, you have two option of passing on xy-coordinates to the function:
(1) Add coordinates to the sample name during measurement. The form is rather
strict and has to follow the scheme _x:<number>|y:<number>. Example:
sample_x:0.2|y:0.4.
(2) Alternatively, you can provide a list or matrix with the (x, y)
coordinates of each sample in meters (m) using the coord argument:
Example: coord = list(c(0.2, 1), c(0.3,1.2))
If in your profile the x-coordinates were not measured, x should be set to 0. Note that, in such case, a surface plot cannot be produced.
RLum.Analysis, RLum.Data.Curve, read_PSL2R
## example profile plot
# (1) load example data set
data("ExampleData.portableOSL", envir = environment())
# (2) merge and plot all RLum.Analysis objects
merged <- merge_RLum(ExampleData.portableOSL)
plot_RLum(
object = merged,
combine = TRUE,
records_max = 5,
legend.pos = "outside")
merged
# (3) analyse and plot
results <- analyse_portableOSL(
merged,
signal.integral = 1:5,
invert = FALSE,
normalise = TRUE)
get_RLum(results)
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